Merge pull request #26955 from DougGregor/simplify-lazy-member-parsing

Simplify lazy member parsing

Author: DougGregor

include/swift/AST/ASTContext.h

@@ -69,7 +69,6 @@ namespace swift {
   class LazyGenericContextData;
   class LazyIterableDeclContextData;
   class LazyMemberLoader;
-  class LazyMemberParser;
   class LazyResolver;
   class PatternBindingDecl;
   class PatternBindingInitializer;
@@ -425,12 +424,6 @@ class ASTContext final {
   void setLazyResolver(LazyResolver *resolver);
 
 public:
-  /// Add a lazy parser for resolving members later.
-  void addLazyParser(LazyMemberParser *parser);
-
-  /// Remove a lazy parser.
-  void removeLazyParser(LazyMemberParser *parser);
-
   /// getIdentifier - Return the uniqued and AST-Context-owned version of the
   /// specified string.
   Identifier getIdentifier(StringRef Str) const;
@@ -822,12 +815,6 @@ class ASTContext final {
   LazyContextData *getOrCreateLazyContextData(const DeclContext *decl,
                                               LazyMemberLoader *lazyLoader);
 
-  /// Use the lazy parsers associated with the context to populate the members
-  /// of the given decl context.
-  ///
-  /// \param IDC The context whose member decls should be lazily parsed.
-  std::vector<Decl *> parseMembers(IterableDeclContext *IDC);
-
   /// Get the lazy function data for the given generic context.
   ///
   /// \param lazyLoader If non-null, the lazy loader to use when creating the

include/swift/AST/DeclContext.h

@@ -51,7 +51,6 @@ namespace swift {
   class GenericParamList;
   class LazyResolver;
   class LazyMemberLoader;
-  class LazyMemberParser;
   class GenericSignature;
   class GenericTypeParamDecl;
   class GenericTypeParamType;

include/swift/AST/LazyResolver.h

@@ -85,21 +85,6 @@ class LazyContextData {
   LazyMemberLoader *loader;
 };
 
-/// A class that can lazily parse members for an iterable decl context.
-class LazyMemberParser {
-public:
-  virtual ~LazyMemberParser() = default;
-
-  /// Retrieves the parsed members for the given decl context \p IDC.
-  virtual std::vector<Decl *> parseMembers(IterableDeclContext *IDC) = 0;
-
-  /// Return whether the iterable decl context needs parsing.
-  virtual bool hasUnparsedMembers(const IterableDeclContext *IDC) = 0;
-
-  /// Parse all delayed decl list members.
-  virtual void parseAllDelayedDeclLists() = 0;
-};
-
 /// Context data for generic contexts.
 class LazyGenericContextData : public LazyContextData {
 public:

include/swift/Parse/Parser.h

@@ -976,15 +976,12 @@ class Parser {
   bool parseMemberDeclList(SourceLoc LBLoc, SourceLoc &RBLoc,
                            SourceLoc PosBeforeLB,
                            Diag<> ErrorDiag,
-                           ParseDeclOptions Options,
                            IterableDeclContext *IDC);
 
   bool canDelayMemberDeclParsing(bool &HasOperatorDeclarations,
                                  bool &HasNestedClassDeclarations);
 
   bool delayParsingDeclList(SourceLoc LBLoc, SourceLoc &RBLoc,
-                            SourceLoc PosBeforeLB,
-                            ParseDeclOptions Options,
                             IterableDeclContext *IDC);
 
   ParserResult<TypeDecl> parseDeclTypeAlias(ParseDeclOptions Flags,

include/swift/Parse/PersistentParserState.h

@@ -26,11 +26,9 @@
 
 namespace swift {
   class AbstractFunctionDecl;
-  class LazyMemberParser;
-  class ASTContext;
 
 /// Parser state persistent across multiple parses.
-class PersistentParserState: public LazyMemberParser {
+class PersistentParserState {
 public:
   struct ParserPos {
     SourceLoc Loc;
@@ -84,34 +82,11 @@ class PersistentParserState: public LazyMemberParser {
     {}
   };
 
-  class DelayedDeclListState {
-    friend class PersistentParserState;
-    friend class Parser;
-    unsigned Flags;
-    DeclContext *ParentContext;
-    ParserPos BodyPos;
-    SourceLoc BodyEnd;
-    SavedScope Scope;
-
-    SavedScope takeScope() {
-      return std::move(Scope);
-    }
-
-  public:
-    DelayedDeclListState(unsigned Flags,
-                     DeclContext *ParentContext, SourceRange BodyRange,
-                     SourceLoc PreviousLoc, SavedScope &&Scope)
-    : Flags(Flags), ParentContext(ParentContext), BodyPos{BodyRange.Start, PreviousLoc},
-      BodyEnd(BodyRange.End), Scope(std::move(Scope))
-    {}
-  };
-
   bool InPoundLineEnvironment = false;
   // FIXME: When condition evaluation moves to a later phase, remove this bit
   // and adjust the client call 'performParseOnly'.
   bool PerformConditionEvaluation = true;
 private:
-  ASTContext &Ctx;
   ScopeInfo ScopeInfo;
   using DelayedFunctionBodiesTy =
       llvm::DenseMap<AbstractFunctionDecl *,
@@ -123,15 +98,15 @@ class PersistentParserState: public LazyMemberParser {
 
   std::unique_ptr<DelayedDeclState> CodeCompletionDelayedDeclState;
 
-  llvm::DenseMap<IterableDeclContext *, std::unique_ptr<DelayedDeclListState>>
-    DelayedDeclListStates;
+  std::vector<IterableDeclContext *> DelayedDeclLists;
 
   /// The local context for all top-level code.
   TopLevelContext TopLevelCode;
 
 public:
   swift::ScopeInfo &getScopeInfo() { return ScopeInfo; }
-  PersistentParserState(ASTContext &Ctx);
+  PersistentParserState();
+  PersistentParserState(ASTContext &ctx) : PersistentParserState() { }
   ~PersistentParserState();
 
   void delayFunctionBodyParsing(AbstractFunctionDecl *AFD,
@@ -146,15 +121,11 @@ class PersistentParserState: public LazyMemberParser {
                  DeclContext *ParentContext,
                  SourceRange BodyRange, SourceLoc PreviousLoc);
 
-  void delayDeclList(IterableDeclContext *D, unsigned Flags,
-                     DeclContext *ParentContext,
-                     SourceRange BodyRange, SourceLoc PreviousLoc);
+  void delayDeclList(IterableDeclContext *D);
 
   void delayTopLevel(TopLevelCodeDecl *TLCD, SourceRange BodyRange,
                      SourceLoc PreviousLoc);
 
-  std::vector<Decl *> parseMembers(IterableDeclContext *IDC) override;
-
   bool hasDelayedDecl() {
     return CodeCompletionDelayedDeclState.get() != nullptr;
   }
@@ -171,14 +142,7 @@ class PersistentParserState: public LazyMemberParser {
     return std::move(CodeCompletionDelayedDeclState);
   }
 
-  std::unique_ptr<DelayedDeclListState>
-    takeDelayedDeclListState(IterableDeclContext *IDC);
-
-  bool hasUnparsedMembers(const IterableDeclContext *IDC) override {
-    return DelayedDeclListStates.find(IDC) != DelayedDeclListStates.end();
-  }
-
-  void parseAllDelayedDeclLists() override;
+  void parseAllDelayedDeclLists();
 
   TopLevelContext &getTopLevelContext() {
     return TopLevelCode;

lib/AST/ASTContext.cpp

@@ -159,10 +159,6 @@ struct ASTContext::Implementation {
   /// The last resolver.
   LazyResolver *Resolver = nullptr;
 
-  /// The lazy parsers for various input files. We may have separate
-  /// lazy parsers for imported module files and source files.
-  llvm::SmallPtrSet<LazyMemberParser*, 2> lazyParsers;
-
   // FIXME: This is a StringMap rather than a StringSet because StringSet
   // doesn't allow passing in a pre-existing allocator.
   llvm::StringMap<char, llvm::BumpPtrAllocator&> IdentifierTable;
@@ -644,16 +640,6 @@ void ASTContext::setLazyResolver(LazyResolver *resolver) {
   getImpl().Resolver = resolver;
 }
 
-void ASTContext::addLazyParser(LazyMemberParser *lazyParser) {
-  getImpl().lazyParsers.insert(lazyParser);
-}
-
-void ASTContext::removeLazyParser(LazyMemberParser *lazyParser) {
-  auto removed = getImpl().lazyParsers.erase(lazyParser);
-  (void)removed;
-  assert(removed && "Removing an non-existing lazy parser.");
-}
-
 /// getIdentifier - Return the uniqued and AST-Context-owned version of the
 /// specified string.
 Identifier ASTContext::getIdentifier(StringRef Str) const {
@@ -2015,16 +2001,6 @@ LazyContextData *ASTContext::getOrCreateLazyContextData(
   return entry;
 }
 
-std::vector<Decl *> ASTContext::parseMembers(IterableDeclContext *IDC) {
-  assert(IDC->hasUnparsedMembers());
-  for (auto *p: getImpl().lazyParsers) {
-    if (p->hasUnparsedMembers(IDC))
-      return p->parseMembers(IDC);
-  }
-
-  return { };
-}
-
 LazyIterableDeclContextData *ASTContext::getOrCreateLazyIterableContextData(
                                             const IterableDeclContext *idc,
                                             LazyMemberLoader *lazyLoader) {

lib/Frontend/Frontend.cpp

@@ -782,7 +782,7 @@ void CompilerInstance::parseAndCheckTypesUpTo(
   std::unique_ptr<DelayedParsingCallbacks> DelayedCB{
       computeDelayedParsingCallback()};
 
-  PersistentState = llvm::make_unique<PersistentParserState>(getASTContext());
+  PersistentState = llvm::make_unique<PersistentParserState>();
 
   bool hadLoadError = parsePartialModulesAndLibraryFiles(
       implicitImports, DelayedCB.get());
@@ -1053,7 +1053,7 @@ void CompilerInstance::performParseOnly(bool EvaluateConditionals,
                                   MainBufferID);
   }
 
-  PersistentState = llvm::make_unique<PersistentParserState>(getASTContext());
+  PersistentState = llvm::make_unique<PersistentParserState>();
 
   SWIFT_DEFER {
     if (ParseDelayedBodyOnEnd)

lib/IDE/REPLCodeCompletion.cpp

@@ -207,7 +207,7 @@ doCodeCompletion(SourceFile &SF, StringRef EnteredCode, unsigned *BufferID,
   // Parse, typecheck and temporarily insert the incomplete code into the AST.
   const unsigned OriginalDeclCount = SF.Decls.size();
 
-  PersistentParserState PersistentState(Ctx);
+  PersistentParserState PersistentState;
   std::unique_ptr<DelayedParsingCallbacks> DelayedCB(
       new CodeCompleteDelayedCallbacks(Ctx.SourceMgr.getCodeCompletionLoc()));
   bool Done;

lib/Immediate/REPL.cpp

@@ -964,7 +964,7 @@ class REPLEnvironment {
       IRGenOpts(),
       SILOpts(),
       Input(*this),
-      PersistentState(CI.getASTContext())
+      PersistentState()
   {
     ASTContext &Ctx = CI.getASTContext();
     Ctx.LangOpts.EnableAccessControl = false;